Despite the fact that Peryite – the Daedric Prince of the Natural Order and Pestilence – is the chief overseer of diseases, it was Molag Bal that created the magical disease known as vampirism. It is commonly thought that the Taskmaster has nothing to do with the disease. However, there are several interesting occurrences where Peryite seems to be connected to the disease.

http://uesp.net/wiki/Daggerfall:Peryite%27s_Quest

"Excellent. It's wonderful seeing a (player's race) with clear objectives. So rare in this day and age. Now then, there's this (Vampire Ancient), frankly a vampire, who I know you'd hate. Thoroughly stupid, unattractive, and mean-spirited sort. He needs to go on a one-way trip to you-know-where." – Peryite

In the this DF quest, Peryite sends you after a Vampire Ancient (whose name is randomly generated) in order for the Player Character to receive the Spellbreaker.

http://images.uesp.net/9/9e/DaggerfallAncientVampire.gif

What I find interesting is that Peryite is hunting down a vampire. Vampirism is commonly referred to as a disease, so it's a possibility. However, at the same time, the Ancient could've just pissed Peryite off. Something else that is interesting to note is that the Worshipper of Peryite that gives you the Spellbreaker upon killing the Ancient is also a vampire.

Onwards to the second.

http://uesp.net/wiki/Morrowind:The_Imprisonment_of_Mastrius

You may come across the vampire Mastrius in the Salvel Ancestral Tomb inside the Ghostfence during your travels. If you are a fellow vampire you can speak to him and learn that he was imprisoned in the tomb by the goddess Azura and that he may have found a way to escape. Mastrius will ask you to bring him the artifact shield Spell Breaker, and a Daedra's Heart. The heart is the easy part, since most Daedra or alchemy shops will have one. – From The MW Quest, The Imprisonment of Mastrius

Once again the Taskmaster (or at least, his chief artifact) is embroiled in a plot involving a vampire. This time, the vampire Mastrius needs the Spellbreaker (and a Daedra Heart) to free himself from with a Dunmer tomb to free himself from a curse by Azura. While it isn't known what he did exactly, Mastrius somehow uses the objects to drain the health and stamina of the Player Character to renew his. Perhaps the curse that Azura used on Mastrius was a disease that Peryite snuck to her, draining his fatigue (leaving him as an immortal being constantly in pain), and so Mastrius had to use Peryite's artifact to make him better? Maybe it's even because the Taskmaster is the DP of Pestilence, and Mastrius thought that since vampirisim is a disease that the Spellbreaker would help him?

Now, let's go the last one.

http://uesp.net/wiki/Skyrim:The_Only_Cure

"Breathe deep, mortal. I would have you hear me well, so let these vapors fill your lungs." – Peryite

This one is shorter, but here is a list of ingredients to invoke Peryite: A Flawless Ruby, Silver Ingot, Deathbell Flowers...and Vampire Dust.

What's with Peryite and Vampires? In this quest, the Player Character has to actually track down and kill a Vampire (unless you know, you just bought it from an alchemy shop in town somewhere) and take the dust from their body just to summon some ghostly apparitions of him at his Shrine.

So, what do you all think? Could Peryite be somewhat connected to vampires?